Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK.
Nat Commun. 2013;4:1402. doi: 10.1038/ncomms2409.
Global-scale deteriorations in coral reef health have caused major shifts in species composition. One projected consequence is a lowering of reef carbonate production rates, potentially impairing reef growth, compromising ecosystem functionality and ultimately leading to net reef erosion. Here, using measures of gross and net carbonate production and erosion from 19 Caribbean reefs, we show that contemporary carbonate production rates are now substantially below historical (mid- to late-Holocene) values. On average, current production rates are reduced by at least 50%, and 37% of surveyed sites were net erosional. Calculated accretion rates (mm year(-1)) for shallow fore-reef habitats are also close to an order of magnitude lower than Holocene averages. A live coral cover threshold of ~10% appears critical to maintaining positive production states. Below this ecological threshold carbonate budgets typically become net negative and threaten reef accretion. Collectively, these data suggest that recent ecological declines are now suppressing Caribbean reef growth potential.
全球范围内珊瑚礁健康状况的恶化导致了物种组成的重大变化。预计的一个后果是珊瑚礁碳酸盐的产生速率降低，这可能会损害珊瑚礁的生长，破坏生态系统功能，并最终导致净珊瑚礁侵蚀。在这里，我们利用来自 19 个加勒比海珊瑚礁的总碳酸盐和净碳酸盐生产和侵蚀的测量结果，表明目前的碳酸盐生产速率现在大大低于历史（中到晚全新世）值。平均而言，目前的生产速率至少降低了 50%，并且 37%的调查地点是净侵蚀的。浅前礁生境的计算附着率（mm 年(-1))也接近全新世平均值的一个数量级。活珊瑚覆盖率约为 10%的阈值似乎对维持正的生产状态至关重要。在这个生态阈值以下，碳酸盐预算通常会变成净负值，并威胁到珊瑚礁的附着。总的来说，这些数据表明，最近的生态衰退正在抑制加勒比海珊瑚礁的生长潜力。
